Working While Receiving Your Pension
You're able to work as an SFPP pensioner without any impact on your payments. Working or contributing to a different pension plan won't change your SFPP pension amount.
If you're collecting your SFPP pension and go back to work for an SFPP employer, you won't be able to make further contributions to the Plan.
Working while collecting an SFPP pension, or receiving income from other sources such as government pensions, may require you to consider requesting additional tax be taken off your SFPP pension payment to avoid owing money at tax time. More about that here.